Grain bins are structures used to store grain. Many farms contain cylindrical grain bins made of a corrugated metal shell on a concrete foundation. Farm grain bins typically have a diameter of about twenty to forty feet, a height of about ten to forty feet, and a capacity of about 3,000 to 50,000 cubic feet (about 2,500 to 40,000 bushels).
Farm grain bins are often constructed with right-angled flashing sections at the interface of the floor and wall located around the perimeter. The flashing sections provide an excellent seal because they are of one piece. The horizontal portions of the flashing sections are attached to the floor and the vertical portions of the flashing sections are attached to the corrugated metal wall. Referring to FIG. 1, a grain bin has a floor 10 comprising horizontal perforated flooring sections 10, a vertical corrugated wall 20, and perforated flashing sections 30 at the interface of the floor and wall. The flashing sections overlie the flooring sections and are attached to the wall with bolts 40 and nuts 50 that project into the interior space of the grain bin. The means for attaching the flashing sections to the floor and the perforations in the floor sections and the flashing sections are omitted from FIG. 1 for clarity.
Many variations of interfaces of the floor and wall in grain bins have been disclosed, including those disclosed in Hagel et al., U.S. Pat. No. 3,925,952, Dec. 16, 1975; Guenther, U.S. Pat. No. 4,287,691, Sep. 8, 1981; Carroll et al., U.S. Pat. No. 4,562,678, Jan. 7, 1986; Brockhaus et al., U.S. Pat. No. 4,589,332, May 20, 1986; and Liefer et al., U.S. Pat. No. 4,709,519, Dec. 1, 1987. The Guenther, Carroll et al., and Brockhaus et al. flashings contain inwardly projecting bolts. The Liefer et al. interface does not contain bolts.
Farm grain bins are typically loaded by conveying the grain in an auger (also known as a screw conveyor) from ground level to the top of the bin. The grain is then dropped down into the center of the bin. Farm grain bins are typically unloaded with a sweep auger that rotates slowly about an anchored center point around the floor of the bin on one or more wheels located at or near the distal end of the auger. The sweep auger moves the grain to a central chute. The grain falls through the central chute and then enters another auger located below the floor that carries the grain to a hopper outside the bin.
A sweep auger does not remove a small volume of grain at the interface of the floor and wall. It is undesirable to leave this grain in the bin for long periods of time because it attracts vermin and insects. Any significant amount of grain left in the bin can also lead to problems with mold. Accordingly, this small amount of grain is typically removed manually with a shovel, a broom, or other tool. The inwardly projecting ends of the bolts can interfere with the tool. Accordingly, there is a demand for a grain bin bolt cover that prevents a shovel, a broom, or other tool from becoming caught on an exposed bolt.